"The fate of this man or that man was less than a drop, although it was a sparkling one, in the great blue motion of the sunlit sea."
During my college years I formed a deep passion for the legends of King Arthur, and over a couple of years I piled up a small but reasonably impressive library of Arthurian books -- novels that retold the legends, novels set in and around the legends, short fiction collections, and a bunch of nonfiction works pertaining to various aspects of Arthuriana and the Celtic legends and mythology that came before. I'm not now the Arthurian that I used to be, but I'll always have a special place in my heart for the Matter of Britain.
I'm not sure if a 'definitive' telling of the Arthur stories has ever been written -- certainly no definitive Arthurian film has yet been made -- but I think that's due to the nature of the legends themselves, which are basically a big collection of stories, many of which aren't really related much at all. The focus is deeply difficult to get right -- is the important part the Arthur-Guinevere-Lancelot triangle? Is it the Round Table and the dream that Camelot represents? Is it the Grail, which is often the hardest part of the story to get right (which is why a lot of retellings leave it out entirely)? I'm not sure.
But one big candidate for the title of "Definitive Arthurian Retelling" is TH White's The Once and Future King, which is just a wonderful, wonderful book. It occurs to me that maybe I'm due for a re-read...and I am planning a whole lot of fantasy reading this winter....